this is a very easy code because I just started learning java.
how do I move the button to specific position/points. Please be brief and make your answer simple and easy to understand because I just started learning java.
this is my code:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class finals extends JFrame implements ActionListener{
JButton login = new JButton("Log-In");
JButton enroll = new JButton("Enroll");
JPanel con = new JPanel();
JFrame frame = new JFrame();
public finals(){
frame.setTitle("Enrollment");
setContentPane(con);
setLayout(new FlowLayout());
login.setLocation(122, 120);
con.add(login);
System.out.println(login.getLocation());
frame.add(con);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300,150);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e){
}
public static void main(String Args[]){
new finals();
}
}
make your answer simple and easy to understand
Don't attempt to specify a pixel location of a component! What is so special about (122, 12)? Nothing, its just a random number you picked.
Let the layout manager do its job. For example you can use a FlowLayout and set the alignment to CENTER so the component is centered on the row.
Or if you don't like that you can use a BoxLayout, and add a "horizontal strut" to the panel to help control positioning.
Read the section from the Swing tutorial on Layout Managers for more information and working examples.
I just started learning java.
Don't forget to check out the Table of Contents from the above tutorial link for more basic information about creating GUI's.
You have to put your JPanel layout to "null".
Just add this : con.setLayout(null);
Related
I am working on a Java desktop application. It uses MySQL database to store all data etc. I use swing for the GUI.
The GUI of this application is layed out as follows:
Main Window taking the entire screen size (with image in the
background)
Internal Window 800 x 600 centered within the Main
Window (that holds current content that can be switched between
using menu and/or event within the application.
LoginPanel.java:
import javax.swing.*;
import java.awt.*;
public class LoginPanel {
private JPanel loginPanel;
public void loginForm()
{
JButton loginSubmit = new JButton("Login");
loginPanel = new JPanel();
loginPanel.add(loginSubmit);
loginPanel.setSize(800, 600);
}
public JComponent getGUI()
{
return loginPanel;
}
public static void main(String[] args)
{
}
}
Main.java:
import javax.swing.*;
import java.awt.*;
public class Main {
public static void main(String[] args)
{
JFrame mainFrame;
mainFrame = new JFrame();
mainFrame.setLayout(new BorderLayout());
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainFrame.setTitle("Caledonian Library System");
LoginPanel loginObj = new LoginPanel();
mainFrame.add(loginObj.getGUI());
mainFrame.pack();
mainFrame.setVisible(true);
}
}
Should I maybe use box layout? any suggestions?
Ok, I have just run a test program, and have achieved the result you are looking for. I have used a GridBagLayout which defaults to centre into the Container it is added to. It will not show up with the borders or other buttons built into a JFrame (though you can add a border if you wish later).
JFrame mainframe = new JFrame();
JPanel mainPanel = new JPanel();
GridBagLayout gridLayout = new GridBagLayout();
mainPanel.setLayout(gridLayout);
//GridBagConstraints allow you to set various features of the way the components appear
//in the grid. You can set this up as you wish, but defaults are fine for this example
GridBagConstraints gridConstraints = new GridBagConstraints();
//Just using FlowLayout as a test for now
JPanel centerPanel = new JPanel(new FlowLayout());
centerPanel.add(new JLabel("Hello"));
centerPanel.add(new JLabel("Centered"));
mainPanel.add(centerPanel, gridConstraints);
mainFrame.add(mainPanel);
If you found that the space around the side of your centered panel wasn't being used, and you wanted it to be use, you could try nesting mainPanel inside another panel that is using a BorderLayout, making sure that it is in BorderLayout.CENTER.
In the example I didn't bother changing GridBagConstraints from the default, as it was ok for this demonstration. However you can edit it as you wish, and then apply to each component you add to the GridBagLayout, making sure to include the GridBagConstraints object in each mainPanel.add(). Check the GridBagLayout tutorials for some good information.
Of course, if you would like more components in the centre other than the main window, you can then simply add them to the mainPanel (making sure to change the position in the GridLayout). There are going to be numerous ways of achieving what you want, but it really depends on what you feel looks good. The Layout Managers will do all of the resizing work for you.
So I would like to have three JButtons all on top of each other, but not to large in width or height either. I am not too familiar with Java's layouts, and to be honest I am not too keen on them. Please view the image a code below to explain to me how, thanks.
package com.aqagame.harrykitchener;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
public class Main
{
private JButton playGame, playerNames, exitGame;
public Main()
{
JPanel mainCard = new JPanel(new BorderLayout(8, 8));
playGame = new JButton("Play Game");
playerNames = new JButton("Player Names");
exitGame = new JButton("Exit Game");
mainCard.add(playGame, BorderLayout.NORTH);
mainCard.add(playerNames, BorderLayout.CENTER);
mainCard.add(exitGame, BorderLayout.SOUTH);
JFrame window = new JFrame("Harry's AQA game");
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.getContentPane().add(mainCard);
window.setSize(900, 800);
window.setLocationRelativeTo(null);
window.setVisible(true);
}
public static void main(String args[])
{
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Main();
}
});
}
}
Check out the Java Documentation for the different layout managers. I know you're not familiar with them, which is why you should probably start. Once you get used to them there is no end to their benefits. There is a lot of excellent information in the documentation and I am sure you will learn a lot. Personally, I recommend looking at the Box Layout:
Create JPanel that uses a GridLayout and add all the buttons to the panel. The GridLayout will automactially size the buttons to be the same size.
Set the layout manager of your main window to use a GridBagLayout.
add the panel to the main window using the default GridBagConststraints. Then the panel will automatically be centered both horizontally and vertically.
To not use Box or GridBag, I think a combination such as this may work out:
Have main panel (let's call it A) have a BorderLayout
Create another panel (let's call it B), with a FlowLayout, with constructor aligning components to the center
Create another panel (let's call it C), with a GridLayout, 1 column 3 rows
Add each button to a new JPanel with a FlowLayout (1 JPanel per button, so buttons are wrapped by a FlowLayout), and then add each of those JPanels to C
Add C to B
Add B to A (center position)
I think this should cause buttons to be on top of each other with small amount of padding while not being stretched widthwise and while appearing in the center of the screen.
I have a default window and its constructor and know what I want all my windows to setup like. Then I want to customize the rest of the windows with their respective interfaces.
import javax.swing.*;
import java.awt.*;
public class Default_window extends JFrame {
protected BorderLayout layout = new BorderLayout();
public Default_window(){
setTitle("My Program");
setLayout(layout);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Dimension Window_size = new Dimension(500,500);
JPanel mypanel= new JPanel();
add(mypanel, BorderLayout.CENTER);
getContentPane();
setResizable(false);
setSize(Window_size);
setVisible(true);
}
}
this is the custom screen I am trying to create:
import javax.swing.*;
public class Login_screen extends Default_window{
JLabel user_name = new JLabel("Username: ");
public Login_screen(){
// insert way to add Jlabels to the panel here.
}
}
But I can't just say add(user_name). It doesnt know where to put it.
Any help is gladly appreciated. I am arecent college grad and no one around me knows anything about programming. #forever_alone
Default_window is extending JFrame, which is a top level container. You have to add your components to your JPanel which you named mypanel.
Try to create a 3rd class that extends JPanel, for example Default_panel and add your components there. Let Login_screen extend Default_panel, and then you will be able to call add(...).
Inheritance in combination with creating a rather complex panel can be very difficult, especially if you want great flexibility (putting plugin components anywhere between the default components). I would therefore suggest to create some GUI builder class, which is responsible for collecting all component constraints, and when every component has been "registered", it can create the JPanel with a LayoutManager of your choice.
If you can avoid a pluggable GUI, avoid it.
(Say) I've created a JPanel with three buttons. I want to place the buttons as follows (I've done this using netbeans GUI editor. But I need to write the whole GUI manually).
Can some one show me a way to achieve this.
(In words, I need to place some buttons right aligned, some other left aligned.)
I guess you want the Configure button to be as far to the left as possible, and the ok and cancel grouped together to the right. If so, I would suggest using a BorderLayout and place the Configure button in WEST, and a flow-layout for Ok, Cancel and place that panel in the EAST.
Another option would be to use GridBagLayout and make use of the GridBagConstrant.anchor attribute.
Since you're taking the time to avoid the NetBeans GUI editor, here's a nice example for you :-)
Code below:
import java.awt.BorderLayout;
import javax.swing.*;
public class FrameTestBase {
public static void main(String args[]) {
// Will be left-aligned.
JPanel configurePanel = new JPanel();
configurePanel.add(new JButton("Configure"));
// Will be right-aligned.
JPanel okCancelPanel = new JPanel();
okCancelPanel.add(new JButton("Ok"));
okCancelPanel.add(new JButton("Cancel"));
// The full panel.
JPanel buttonPanel = new JPanel(new BorderLayout());
buttonPanel.add(configurePanel, BorderLayout.WEST);
buttonPanel.add(okCancelPanel, BorderLayout.EAST);
// Show it.
JFrame t = new JFrame("Button Layout Demo");
t.setContentPane(buttonPanel);
t.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
t.setSize(400, 65);
t.setVisible(true);
}
}
I am really new to GUI programming in Java, I did a lot of research and I couldn't find an answer to this problem.
I have a simple JFrame with a menu, and inside this JFrame I have a JPanel with a log in form (were users input their username and password), and then I want to change that JPanel to another JPanel depending on what users want to do.
What would be the best way of doing this? I think that stacking JPanels is OK. But after I add new JLayeredPanels in Netbeans they don't stack. I read somewhere that I should use Z ordering or something like that, but I can't find it on the designer view.
Well, thank you very much for your patience!
CardLayout class has a useful API that can serve your requirements. Using methods like next(), first(), last() can be helpful.
I've prepared a simple demonstration of changing panels within a parent panel and/or frame.
Take a look at it:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class PanelChanger implements ActionListener
{
JPanel panels;
public void init(Container pane)
{
JButton switcher = new JButton("Switch Active Panel!");
switcher.addActionListener(this);
JPanel login = new JPanel();
login.setBackground(Color.CYAN);
login.add(new JLabel("Welcome to login panel."));
JPanel another = new JPanel();
another.setBackground(Color.GREEN);
another.add(new JLabel("Yeah, this is another panel."));
panels = new JPanel(new CardLayout());
panels.add(login);
panels.add(another);
pane.add(switcher, BorderLayout.PAGE_START);
pane.add(panels, BorderLayout.CENTER);
}
public void actionPerformed(ActionEvent evt)
{
CardLayout layout = (CardLayout)(panels.getLayout());
layout.next(panels);
}
public static void main(String[] args)
{
JFrame frame = new JFrame("CardLayoutDemo");
PanelChanger changer = new PanelChanger();
changer.init(frame.getContentPane());
frame.pack();
frame.setVisible(true);
}
}